Historically, the effective strength of a column never approaches the ultimate strength of the material it's made of, because failure always precedes it due to inherent weaknesses in its shape. A column is a structural unit carrying loads which act parallel to the longitudinal axis of the member. If the applied load is eccentric to the axis, there is a lateral deflection and a resultant bending stress which combine with the direct compression and ultimately lead to failure of the member due to buckling. If the load could be applied exactly coincident with the longitudinal axis . . . if the member were perfectly straight . . . and if the material were homogeneous . . . then the column would be stressed in pure compression.
Heretofore, it's been impossible to produce this ideal member, and columnar design has had to factor in an equivalent eccentricity of load by using the empirically formulated Slenderness Ratio L/D . . . which is the laterally unsupported column length L divided by the minimum cross-section width, or diameter D. The tendency of the column to deflect laterally and develop bending stresses increases with L and decreases with D, so the taller the column . . . the weaker the section, and the shorter . . . the stronger. Hence, in the prior art the ultimate strength of a column has been governed more by its geometry . . . than what it's made of.
The present invention maximizes the strength of a pure column by negating its inherent weakness, the elongation, by reducing the laterally unsupported length and thus the Slenderness Ratio . . . to zero, by total encapsulation in and adhesion to plastic foam. This allows it as a homogeneous material to perform at ultimate strength, maximizing efficiency while minimizing material need. Here, although it carries no direct axial load, the plastic foam neutralizes the equivalent eccentricity of load, facilitates the pure compression of an ideal member, supercharges column ability, generates synergy . . . and supersedes history.
The intention here is to conquer the essence of this synergy . . . and domesticate it. With elongate structure adhered to and encapsulated by a core of plastic foam, the resultant composite is not only strong, resilient and moisture resistant but also ideal for building construction with a strength to weight ratio up to a thousand to one. With endless possibilities for longer spans, greater cantilevers, three-dimensional module building, and ultra-lite assembly systems, it's so novel that it puts a whole new dimension on architectural concepts and, with a myriad of applications, facilitates a new technology.
However, in building construction plastic foam has vices as well as virtues. As a foam structure it's hard to analyze and as a material it's chemically volatile. Thus it's totally dependent on and limited by empirical testing for every structural application, which is expensive and time-consuming, and drywall or its equivalent for every habitable use, items which are usually heavy, brittle and the antithesis of the foam's intrinsic nature.
The obvious technological potential here is prefabrication. But since the beginning of the industrial revolution, people have been trying unsuccessfully to minimize on-site labor costs with prefabricated panels. Over the years only two panels have proved viable and enduring, drywall and plywood, and neither of these are load-bearing . . . just facings. Other than that, today's house is still being built stick by stick just as it was long ago. The dilemma with structural panels is access and finish in that, after installation, internal access is ordinarily required for the placement of utility lines and overly finished panels tend to be inaccessible. If the pipes and wires are pre-installed per panel, splices between panels reduce line efficiency, increase labor, and defeat the purpose of prefabrication. Also, finished panels have abutting edges which are impossible to hide or relate to adjacent spaces. Hence, the ideal building panel would be a semi-finished load-bearing structure, with constant and convenient internal access, of an approved heat and fire resistant material, with cost-savings both in expedient manufacture and systematic on-site assembly.